[jboss-user] [Performance Tuning] - Server Hangs, Optimization issues

[Karthikeyan Duraisamy]

Karthikeyan Duraisamy [https://community.jboss.org/people/karthykn] created the discussion

"Server Hangs, Optimization issues"

To view the discussion, visit: https://community.jboss.org/message/817573#817573

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Hi,

I am quiet new here. forgive if my questions are dump.

We are having a problem on JBoss(Version: 5.0.0.CR2) server running with Jrockit(Version :build R27.6.5-32_o-121899-1.6.0_14-20091001-2107-windows-ia32)
The server hang frequently.

was trying to optimize the JVM settings.

Initial JVM setting was : *set JAVA_OPTS=%JAVA_OPTS% -Xms768m -Xmx1024m -XX:MaxPermSize=256m*

Later have chaged to

*set JAVA_OPTS=%JAVA_OPTS% -Xms1024m -Xmx1024m -Xns512m -XXkeepAreaRatio=3 -XXsetGC:genparcon -XXcompactSetLimit:10200 -Xverbose:gc -Xverboselog:jbossVerboseLog.txt*

But getting some page fault errors as shown below,
+[INFO ][memory ] Warning: Your computer has generated 31142 page faults during the last garbage collection.+
+[INFO ][memory ] If you find this swapping problematic, please consider running JRockit with a smaller heap.+

After few hours it started  Throwing OutOfMemory: allocLargeObjectOrArray

So I included the XXtlaSize in jvm settings,

*set JAVA_OPTS=%JAVA_OPTS% -Xms1024m -Xmx1024m -Xns512m -XXlargeObjectLimit=70k -XXtlaSize=70k -XXminBlockSize=96k -XXkeepAreaRatio=3 -XXsetGC:genparcon -XXcompactSetLimit:10200  -Xverbose:gc -Xverboselog:jbossVerboseLog.txt*

But server become very unstable, server restarted automatically.

Now we revert all the changes to initial settings.

I have attached verbose log. Please suggest me in case if i need to look into something else.

Thanks in advance.
Karthik
+*
*+
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[Peter Johnson]

Peter Johnson [https://community.jboss.org/people/peterj] created the discussion

"Re: Server Hangs, Optimization issues"

To view the discussion, visit: https://community.jboss.org/message/817651#817651

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Sorry, I can't help you with JRockit. But I do have some questions:
1) Why are you running 5.0.0.CR2? That is not even a released version. And even the released version of 5.0.0.GA was sort of flakey. You should really be running with at least 5.0.1.GA or better yet 5.1.0.GA.
2) Have you tried running with the Oracle JDK instead? If the problems are really with JRockit, then switching JVMs might help.
3) I have no idea about the ability of JRockit to perform a heap dump on an out of memory error. Can it do that? If so, have you done that and analyzed the dump to see which objects are taking up the heap space?
Randomly setting JVM options without knowing the root cause of the problem is fairly useless.
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